To build more lay boxes or not?

Greetings! I have a question regarding how many lay boxes I should have in my coop.

So I have 22 chickens total, 2 flocks, 2 different ages.

When I first built my coop I was in a hurry to get my first batch in because they were growing so fast. I originally built 3 lay boxes and put in one set of roosts for 10 hens. Now all ten are laying and seem to be very pleased in their home. All but 3 girls lay their eggs in the exact same box. The other 3 love laying behind the feed containers.

Then I added 12 more girls in the coop. I immediately built more roosts and my plan was to add more boxes once it got closer to their laying time.

Now 2 of my second batch are laying. I must admit I have been a bit lazy lately and have yet to put more lay boxes in. I've noticed though that the newest 2 laying are laying in the same box as all the other hens.

Occasionally I will find 1-3 eggs in a different box from the rest but that's it.

So my question is, should I still add more boxes in my coop? I know only 3 seems like not enough for 22 chickens but it seems that they all prefer to use the same one anyways.

If only 2 of the second flock are laying, it's going to get too crowded! An easy way to give them more nests is to put 5 gallon buckets on their side with some straw in them. It's a good temporary fix.